I use Tor Browser. At times I want to connect directly without Tor or any other proxy in Firefox. Can I turn off Tor and use Firefox only? (Tor button used to do something like this as far as I remember, but now it doesn't seem to do it.)
You should probably install a regular version of Firefox and use the Tor Browser for when you want to use Tor.
This has various benefits. The Tor Browser Bundle includes a version of Firefox that is a fork, which means it has a modified source code in order to increase your privacy/anonymity.
The Tor Browser is run highly separated. You can run the Tor Browser and a regular Firefox instance at the same time. The configuration is completely separate. This prevents you from leaking information that would allow an attacker to determine who you are, even when using Firefox with Tor.
Since you also shouldn't use any other plugins (Flash, Java, ...) or Firefox Add-ons in order to not accidentally leak information on who you are it is way safer to use both the Tor Browser and Firefox as separate instances.
It's was answered here: Connect directly with Tor Browser (as in, bypass Tor)?. Quoting the best answer:
You have to disable Torbutton.
At the top of the connection settings dialog, it indicates this: "Disable Torbutton to change these settings."
about:addonsyou can disable Torbutton and TorLauncher and then quit/relaunch the browser. Then you can set your own proxy settings or none in the network connection settings.
Edit to add: If you don't use a proxy, you must also disable
Remote DNSin network connection settings. Even thought it is greyed out when
No Proxyis selected, it must be unchecked.
Edit: Better and more complete instructions:
about:addonsin the URL bar.
In that page, disable Torbutton and TorLauncher add-ons.
Restart the browser as prompted.
Click on Menu (3 horizontal bars logo located at top-left) > Preferences/Options > Advance vertical tab > Network horizontal tab.
Click on the Settings button on the right of "Connection" label (while you are in that tab) which opens up the proxy configuration window.
Untick Remote DNS checkbox (At center-right of the window).
Change your proxy settings accordingly to your own proxy or to no proxy and click OK.
Congratulations have de-torified the Tor browser!
P.S. Thanks you, Peter Gerber